Display device including a crack detection line

ABSTRACT

A display device includes a substrate including a display area and a non-display area. The display device further includes a plurality of pixels in the display area of the substrate. The display device additionally includes a plurality of gate lines and a plurality of data lines respectively connected to the plurality of pixels. The display device further includes a plurality of insulative step portions disposed in the non-display area of the substrate and arranged in a first direction parallel to sides of the display area. The display device further includes a crack detection line in the non-display area and extending primarily in the first direction. The crack detection line includes a first portion which does not overlap the plurality of insulative step portions, and a second portion overlapping each of the insulative step portions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/457,066 filed Mar. 13, 2017, which claims priority under 35 USC § 119to Korean Patent Application No. 10-2016-0030417 filed on Mar. 14, 2016in the Korean Intellectual Property Office, the disclosures of which areincorporated by reference herein in their entireties.

TECHNICAL FIELD

The present disclosure relates to a display device, and moreparticularly, to a display device including a crack detection line.

DISCUSSION OF THE RELATED ART

Currently, portable display devices are being developed so that they areflexible instead of being rigid. As portable display devices are furtherdeveloped, the display device may be changed from a flat form to aflexible form.

When a crack is generated during a manufacturing process of the displaydevice, moisture and the like may permeate into a display area of thedisplay device. The permeation of moisture and the like through thecrack may cause a defect in the display device.

SUMMARY

According to an exemplary embodiment of the present disclosure, adisplay device includes a substrate including a display area and anon-display area. The display device further includes a plurality ofpixels in the display area of the substrate. The display deviceadditionally includes a plurality of gate lines and a plurality of datalines respectively connected to the plurality of pixels. The displaydevice further includes a plurality of insulative step portions disposedin the non-display area of the substrate and arranged in a firstdirection repeatedly to sides of the display area. The display devicefurther includes a crack detection line in the non-display area andextending primarily in the first direction. The crack detection lineincludes a first portion which does not overlap the plurality ofinsulative step portions, and a second portion overlapping each of theinsulative step portions.

In an exemplary embodiment of the present invention, the first portionand the second portion of the crack detection line are at differentheights from each other.

In an exemplary embodiment of the present invention, the second portionof the crack detection line is on a surface of an upper portion of aninsulative step portion of the plurality of insulative step portions,and the first portion of the crack detection line is at substantiallythe same height as that of a lower portion of the insulative stepportion of the plurality of insulative step portions.

In an exemplary embodiment of the present invention, the crack detectionline is connected to at least one data line of the plurality of datalines.

In an exemplary embodiment of the present invention, the crack detectionline at least partially surrounds the display area of the substrate.

In an exemplary embodiment of the present invention, the plurality ofinsulative step portions includes an organic material or an inorganicmaterial, and at least partially surrounds the display area of thesubstrate.

In an exemplary embodiment of the present invention, the second portionis on substantially the same layer as that of the data line, and thecrack detection line includes substantially the same material as that ofthe data line.

In an exemplary embodiment of the present invention, the first portionis directly on the substrate.

In an exemplary embodiment of the present invention, the display devicefurther includes an insulating layer on the substrate. The first portionis on the insulating layer.

In an exemplary embodiment of the present invention, the display devicefurther includes an active layer connected with the data line. The firstportion is at substantially the same height as that of the active layer.

In an exemplary embodiment of the present invention, the plurality ofinsulative step portions have substantially the same form.

In an exemplary embodiment of the present invention, a part of the crackdetection line is divided into a first line and a second line.

In an exemplary embodiment of the present invention, a sum ofthicknesses of the first line and the second line is equal to or smallerthan a thickness of the crack detection line.

According to an exemplary embodiment of the present invention, a displaydevice includes a substrate including a first area and a second areasurrounding the first area. The display device further includes aplurality of insulative step portions disposed in the non-display areaof the substrate and arranged in a first direction repeatedly to a sideof the display area. The display device additionally includes a crackdetection line in the second area and extending primarily in the firstdirection. The crack detection line includes a first portion and aplurality of second portions. The first portion is between eachinsulative step portion of the plurality of insulative step portions,and the second portion overlaps each of the insulative step portions.

In an exemplary embodiment of the present invention, the first portionis on the substrate, and the first portion and the second portion are atdifferent heights from each other.

In an exemplary embodiment of the present invention, the first portionand the second portion are connected to each other along a lateral wallof each insulative step portion of the plurality of insulative stepportions.

In an exemplary embodiment of the present invention, the crack detectionline is divided into a plurality of lines, and the plurality of linesrecombine near a first end and a second end of the crack detection line.

According to an exemplary embodiment of the present invention, a displaydevice includes a substrate including a display area and a non-displayarea surrounding the display area. The display device further includes aplurality of insulative step portions disposed in the non-display areaand arranged in a first direction parallel to a side of the display witha predetermined interval. The display device additionally includes acrack detection line on the plurality of insulative step portions. Thecrack detection line includes a first portion and a second portion. Thesecond portion overlaps an upper portion of an insulative step portionof the plurality of insulative step portions and the first portion isadjacent to at least one insulative step portion of the plurality ofinsulative step portions.

In an exemplary embodiment of the present invention, the first portionand second portion have a curvature.

In an exemplary embodiment of the present invention, the first portionis on the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present disclosure and many of theattendant aspects thereof will be readily obtained as the same becomesbetter understood by reference to the following detailed descriptionwhen considered in connection with the accompanying drawings, wherein:

FIG. 1 is a cross-sectional view of a display device according to anexemplary embodiment;

FIG. 2 is a top plan view schematically illustrating a disposition of acrack detection line in a display device according to an exemplaryembodiment;

FIG. 3 is a layout view of the display device according to an exemplaryembodiment;

FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a waveform diagram of a signal of the display device accordingto an exemplary embodiment;

FIG. 6 is a top plan view schematically illustrating a disposition of acrack detection line in a display device according to an exemplaryembodiment;

FIG. 7 is a layout view of the display device according to an exemplaryembodiment;

FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 6;and

FIG. 9 is a schematic cross-sectional view of a display device accordingto an exemplary embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments of the present invention will be described in moredetail below with reference to the accompanying drawings, in whichexemplary embodiments of the preset invention are shown.

In describing the present invention, parts that are not related to thedescription will be omitted. Like reference numerals may designate likeelements throughout the specification and the drawings.

In addition, the size and thickness of each configuration shown in thedrawings may be exaggerated for better understanding and ease ofdescription, but the present invention is not limited thereto. In thedrawings, the thickness of layers, films, panels, regions, etc., may beexaggerated for clarity.

Further, it will be understood that when an element such as a layer,film, region, or substrate is referred to as being “on” another element,it can be directly on the other element or intervening elements may alsobe present.

Further, when an element is referred to as being “above” or “on” a partserving as a reference, the element may be positioned on or under thereference part, and it does not mean that the element is essentiallypositioned “above” or “on” in a direction opposite to gravity.

First, a display device according to an exemplary embodiment will bedescribed with reference to FIG. 1. FIG. 1 is a cross-sectional view ofa display device according to an exemplary embodiment.

The display device according to the exemplary embodiment includes adisplay area, which includes a plurality of pixels and displays animage, and a non-display area, in which various wires are positioned andwhich does not display an image. A first area A of FIG. 1 represents across-section of a part of one pixel in the display area of the displaydevice. A second region B of FIG. 1 represents a cross-section of aportion of the non-display area of the display device, through which acrack detection line CD passes, taken along in a direction parallel toan extension direction of the crack detection line CD.

Referring to the first area A of FIG. 1, the display device includes asubstrate SUB, and a thin film transistor TFT is positioned on thesubstrate SUB. The thin film transistor TFT includes an active layer AL,a gate electrode GE, a source electrode SE, and a drain electrode DE.The gate electrode GE is connected to a gate line, and the sourceelectrode SE is connected to a data line.

The active layer AL may be formed of polysilicon or an oxidesemiconductor. The active layer AL may include a channel area, which isnot doped with impurities. A source area and a drain area, may bepositioned at both sides of the channel area and are doped withimpurities. A first insulating layer IL1 may be positioned between thesubstrate SUB and the thin film transistor TFT.

The gate electrode GE is positioned on the active layer AL with a secondinsulating layer IL2 interposed therebetween. Further, the thirdinsulating layer IL3 may be positioned on the gate electrode GE suchthat the gate electrode GE is covered. A fourth insulating layer IL4 maybe positioned on the third insulating layer IL3. Accordingly, the fourthinsulating layer IL4 covers gate electrode GE. The source electrode SEand the drain electrode DE may be positioned on the fourth insulatinglayer IL4 and may be connected to the source area and the drain area ofthe active layer AL through respective contact holes formed in thesecond insulating layer IL2, the third insulating layer IL3, and thefourth insulating layer IL4. The drain electrode DE is connected to afirst electrode E1 of an organic light emitting diode OLED through acontact hole formed in a fifth insulating layer IL5. In an exemplaryembodiment, the gate electrode may be positioned on the active layer AL.The present invention is not limited thereto. For example, the gateelectrode GE may be positioned under the active layer AL.

The organic light emitting diode OLED includes the first electrode E1connected with the drain electrode DE of the thin film transistor TFT,an organic emission layer EL positioned on the first electrode E1, and asecond electrode E2 positioned on the organic emission layer EL. A sixthinsulating layer IL6 may be positioned on the first electrode E1 todefine a section, in which the organic emission layer EL may bepositioned. For example, the sixth insulating layer IL6 may partiallycover the first electrode EL1.

The first electrode E1 may be an anode that may be a hole injectionelectrode, and the second electrode E2 positioned on the organicemission layer EL may be a cathode that may be an electron injectionelectrode. However, the present invention is not limited thereto. Forexample, the first electrode E1 may be a cathode that may be an electroninjection electrode, and the second electrode E2 positioned on theorganic emission layer EL may be an anode that may be a hole injectionelectrode.

The organic emission layer EL may be positioned between the firstelectrode E1 and the second electrode E2, and may include a lowmolecular organic material or a polymer organic material, such as poly3,4-ethylenedioxythiophene (PEDOT). The organic emission layer EL mayinclude a red organic emission layer for emitting red light, a greenorganic emission layer for emitting green light, and a blue organicemission layer for emitting blue light. Further, the red organicemission layer, the green organic emission layer, and the blue organicemission layer are formed in a red pixel, a green pixel, and a bluepixel, respectively, to produce an image with color.

An encapsulating unit EN may cover the substrate SUB and may seal theorganic light emitting diode OLED interposed therebetween. Further, theencapsulation unit EN may seal the display area. The encapsulating unitEN may include an organic layer OL and an inorganic layer IL positionedon the organic layer OL.

Referring to the second area B of FIG. 1, a plurality of insulative stepportions ILp is repeatedly arranged in the non-display area with apredetermined interval in a predetermined direction. The plurality ofinsulative step portions ILp may have substantially the same form (e.g.,shape), or each insulative step portion ILp may have different forms.For example, each insulative step portion ILp may have different heightsand/or widths. The plurality of insulative step portions ILp may bedisposed in the non-display area so as to surround the display area. Theplurality of insulative step portions ILp may provide a step portion tothe crack detection line CD to be described below. For example, thecrack detection line CD may be disposed on insulative step portions ILpand between each insulative step portion ILp. The plurality ofinsulative step portions ILp may include an organic material or aninorganic material. The plurality of insulative step portions ILp mayinclude at least a part of the sequentially disposed first to fourthinsulating layers IL1, IL2, IL3, and IL4.

The crack detection line CD may extend in a direction in which theplurality of insulative step portions ILp may be repeatedly disposed.Further, the crack detection line CD may be positioned on the pluralityof insulative step portions ILp. The direction, in which the pluralityof insulative step portions ILp may be repeatedly disposed, correspondsto the extension direction of the crack detection line CD. The extensiondirection of the crack detection line CD means a direction of a longside, not a direction of a short side, of the crack detection line CD.The crack detection line CD may be disposed on the plurality ofinsulative step portions ILp so as to at least partially surround thedisplay area.

The crack detection line CD includes a plurality of stepped wiring unitsCDp, which may be repeatedly positioned in the extension direction ofthe crack detection line CD. The stepped wiring unit CDp includes afirst portion CDpa, which does not overlap the insulative step portionILp, and a second portion CDpb, which overlaps the insulative stepportion ILp. The plurality of stepped wiring units CDp may becontinuously disposed in the direction, in which the plurality ofinsulative step portions ILp may be repeatedly disposed. The secondportion CDpb of the stepped wiring unit CDp may cover a surface of theinsulative step portion ILp that faces a surface of the substrate SUB.The insulative step portion ILp may be positioned under at least a partof the stepped wiring unit CDp.

The stepped wiring unit CDp includes a first portion CDpa having a lowersurface positioned at substantially the same height as that of a lowersurface of the insulative step portion ILp and a second portion CDpbpositioned on an upper surface of the insulative step portion ILp.Further, the first portion CDpa and the second portion CDpb areconnected along a lateral wall of the insulative step portion ILp. Forexample, the second portion CDpb overlaps the insulative step portionILp, and the first portion CDpa does not overlap the insulative stepportion ILp. Accordingly, the first portion CDpa and the second portionCDpb have a height difference corresponding to a height of theinsulative step portion ILp. Here, the height is based on a directionvertical to a surface, on which the insulative step portions ILp may bedisposed, of the substrate SUB. For example, the surface of substrateSUB, of which the height is based on, may be a top surface of thesubstrate SUB.

As described above, the crack detection line CD has a form, in which thesecond portion CDpb and the first portion CDpa having the heightdifference corresponding to the height of the insulative step portionILp are repeated in the extension direction of the crack detection lineCD. For example, the second portion CDpb of the crack detection line CDmay be positioned on substantially the same layer as that of the dataline and the source electrode SE, and the first portion CDpa of thecrack detection line CD may be positioned on the substrate SUB. However,the first portion CDpa of the crack detection line CD may be positionedon the first insulating layer IL1 positioned on the substrate SUB. Thecrack detection line CD may include the same material as that of thedata line and the source electrode SE.

Hereinafter, a display device according to an exemplary embodiment willbe described in detail based on a crack detection line with reference toFIGS. 2 to 4. FIG. 2 is a top plan view schematically illustrating adisposition of a crack detection line in a display device according toan exemplary embodiment. FIG. 3 is a layout view of the display deviceaccording to an exemplary embodiment, and FIG. 4 is a cross-sectionalview taken along line IV-IV of FIG. 2.

The substrate SUB of the display device according to an exemplaryembodiment may be an insulative substrate made of, for example, glass,polymer, or stainless steel. The substrate SUB may be flexible,stretchable, foldable, bendable, rollable, etc. For example, thesubstrate SUB may have a flexible film form including a resin, such aspolyimide.

The substrate SUB includes a display area DA for displaying an image anda non-display area NDA positioned in a border region around of thedisplay area DA (e.g., a peripheral area of the display area). In anexemplary embodiment, the non-display area NDA is positioned so as tosurround the display area DA, but according to an exemplary embodiment,the non-display area NDA may be positioned along one side, two sides, orthree sides of the display area DA.

The display area DA of the substrate SUB includes a plurality of pixelsR, G, and B. The pixel is a minimum unit for displaying an image.

An encapsulating unit EN may be positioned on the substrate SUBoverlapping the entirety of the display area DA and the non-display areaNDA of the substrate SUB. The encapsulating unit EN covers the substrateSUB with the plurality of pixels R, G, and B interposed therebetween andseals the display area DA. The encapsulating unit EN may include anorganic layer OL and an inorganic layer IL positioned on the organiclayer OL. The encapsulating unit EN may be a thin film encapsulatingunit. According to an exemplary embodiment, the encapsulating unit ENmay include one or more organic layers and one or more inorganic layers,which may be alternately disposed. However, the present invention is notlimited thereto, and the number of inorganic layers or organic layersmay be, for example, two or more, and the plurality of inorganic layersand the plurality of organic layers may be alternately disposed. Forexample, the encapsulating unit EN may be a multi-layered structure.Further, the multi-layered structure may include one or more sandwichstructures, in which one or more organic layers may be inserted betweentwo or more inorganic layers.

The display device according to an exemplary embodiment may include aplurality of signal lines connected to the plurality of pixels R, G, andB. At least a part of the plurality of signal lines is positioned in thenon-display area NDA of the substrate.

The plurality of signal lines may include a first test gate lineTEST_GATE, a second test gate line DC_GATE, a plurality of data lines D,a first test signal line TEST_DATA1, a plurality of second data signallines CLA, CLB, and CLC, a first crack detection line CD1, and a secondcrack detection line CD2.

A control terminal of a first switching element Q1 positioned in thenon-display area NDA of the substrate is connected to the first testgate line TEST_GATE, and an input terminal thereof is connected to thefirst test signal line TEST_DATA1. Further, an output terminal of thefirst switching element Q1 is connected to the data line D. The outputterminal of the first switching element Q1 may be connected to theplurality of data lines D.

A control terminal of a second switching element Q2 is connected to thesecond test gate line DC_GATE, and an input terminal thereof isconnected to one of the second test signal lines CLA, CLB, and CLC.Further, an output terminal of the second switching element Q2 isconnected to the data line D. A first pixel R among the plurality ofpixels R, G, and B may be connected to a second-one test signal line CLAthrough the second switching element Q2. The second pixel G may beconnected to a second-two test signal line CLB through the secondswitching element Q2, and a third pixel B may be connected to asecond-three test signal line CLC through the second switching elementQ2.

The first crack detection line CD1 and the second crack detection lineCD2 may be disposed at both sides (e.g., left and right) of the displayarea DA, respectively, so as to at least partially surround the displayarea DA, in which the plurality of pixels R, G, and B is positioned.

The first crack detection line CD1 may be connected to at least one ofthe plurality of data lines D through a first connection portion CP1 aand a second connection portion CP1 b. The data line D connected withthe first crack detection line CD1 may be connected to the second-twotest signal line CLB. One end of the first crack detection line CD1 maybe connected to the input terminal of the second switching element Q2through the second connection portion CP1 b.

The first crack detection line CD1 extends in a first direction R1 fromthe first connection portion CP1 a along the non-display area NDAadjacent to the border of the display area DA, in which the plurality ofpixels R, G, and B is formed, and then changes a direction and isextended in a second direction R2 that is an opposite direction to thefirst direction R1. Further, the first crack detection line CD1 isconnected with another wire through the second connection portion CP1 b.

Similarly, the second crack detection line CD2 is connected to at leastone of the plurality of data lines D through a third connection portionCP2 a and a fourth connection portion CP2 b. The data line D connectedwith the second crack detection line CD2 may be connected to thesecond-two test signal line CLB. One end of the second crack detectionline CD2 may be connected to the input terminal of the second switchingelement Q2 through the fourth connection portion CP2 b.

The second crack detection line CD2 extends in the first direction R1from the third connection portion CP2 a along the non-display area NDAadjacent to the border of the display area DA, in which the plurality ofpixels R, G, and B is formed, and then changes a direction and isextended in the second direction R2 that is the opposite direction tothe first direction R1. Further, the second crack detection line CD2 isconnected with another wire through the fourth connection portion CP2 b.

The first crack detection line CD1 and the second crack detection lineCD2 may extend in the first direction R1 so as to at least partiallysurround the display area DA and then return along the second directionR2 that is the opposite direction to the first direction R1. Forexample, the first direction R1 may extend parallel to sides of thedisplay area DA.

The first crack detection line CD1 includes a plurality of repeatedlypositioned stepped wiring units CDp. The stepped wiring unit CDpincludes a first portion CDpa and a second portion CDpb having differentheights from each other based on a direction vertical to the top surfaceof the substrate SUB. The first crack detection line CD1 may have aform, in which the first portion CDpa and the second portion CDpb arerepeatedly present in an extension direction of the first crackdetection line CD1, so that a predetermined height difference isrepeated.

The stepped wiring unit CDp of the first crack detection line CD1includes a second portion CDpb of the stepped wiring unit CDpoverlapping the insulative stepped portion ILp and a first portion CDpa,which does not overlap the insulative stepped portion ILp. For example,the insulative step portion ILp may be positioned under a part of thestepped wiring unit CDp. The insulative step portion ILp provides a stepto the first crack detection line CD1, and a height of a surface of thefirst crack detection line CD1 is changed according to whether the firstcrack detection line CD1 overlaps the insulative step portion ILp.

The plurality of insulative step portions ILp is repeatedly disposed inthe extension direction of the first crack detection line CD1 with apredetermined interval. The plurality of insulative step portions ILpmay have substantially the same form or different forms, such as heightsor widths. The plurality of insulative step portions ILp may be disposedso as to surround the display area DA. The plurality of insulative stepportions ILp may be made of an organic material or an inorganicmaterial. The plurality of insulative step portions ILp may include atleast a part of the sequentially disposed first to fourth insulatinglayers IL1, IL2, IL3, and IL4.

The second portion CDpb of the stepped wiring unit CDp is positioned ona surface of an upper portion of the insulative step portion ILp, andthe first portion CDpa may be positioned at substantially the sameheight as that of the lower portion of the insulative step portion ILp.For example, the first portion CDpa may be positioned on substantiallythe same layer as that of the lower portion of the insulative stepportion ILp. The first portion CDpa and the second portion CDpb areconnected along a lateral wall of the insulative step portion ILp. Thefirst portion CDpa and the second portion CDpb have a height differencecorresponding to a height of the insulative step portion ILp. Forexample, the second portion CDpb overlaps the insulative step portionILp, and the first portion CDpa does not overlap the insulative stepportion ILp. Accordingly, the first crack detection line CD1 has a form,in which the high second portion CDpb and the low first portion CDpahaving the height difference corresponding to the height of theinsulative step portion ILp are repeated in the extension direction ofthe first crack detection line CD1.

The second portion CDpb of the first crack detection line CD1 may bepositioned on substantially the same layer as that of the data line D,and the first portion CDpa of the first crack detection line CD1 may bepositioned on the substrate SUB. However, the first portion CDpa of thecrack detection line CD may be positioned on a first insulating layerIL1 positioned on the substrate SUB. The first crack detection line CD1may include substantially the same material as that of the data line D.

Similarly, the second crack detection line CD2 may also include astepped wiring unit CDp including the first portion CDpa and the secondportion CDpb having a height difference corresponding to the height ofthe insulative step portion ILp. Further, the forms of the first crackdetection line CD1 and the second crack detection line CD2 may besubstantially the same as each other.

In the above, the preferable structure of the display device accordingto an exemplary embodiment of the present invention has been described,but the present invention is not limited thereto, and variousmodifications may be made within the scope of the inventive concept ofthe present invention. For example, one end of the first crack detectionline CD1 may be connected to an output terminal of the second switchingelement Q2, and the second crack detection line CD2 may be connected toan output terminal of the second switching element Q2.

Further, the data line D connected with the first crack detection lineCD1 and the data line D connected with the second crack detection lineCD2 may each be connected with the second-one test signal line CLA orthe second-three test signal line CLC, and might not be connected withthe second-two test signal line CLB. Further, the first crack detectionline CD1 and the second crack detection line CD2 may be connected to thedata lines connected to the different test signal lines, respectively.

Further, the insulative step portion ILp may include at least a part ofthe sequentially disposed second to fourth insulative layers IL2, IL3,and IL4, and thus, may have substantially the same height as that of thesequentially disposed second to fourth insulative layers IL2, IL3, andIL4. Accordingly, the first portion CDpa and the second portion CDpb mayhave a height difference corresponding to the height of the second tofourth insulative layers IL2, IL3, and IL4 sequentially disposed.

Hereinafter, an operation and an effect of the display device accordingto an exemplary embodiment of the present invention will be describedwith reference to FIGS. 3 to 5. FIG. 5 is a waveform diagram of a signalof the display device according to an exemplary embodiment.

When a gate on signal is applied to the first test gate line TEST_GATEfor a first time H1, the plurality of first switching elements Q1connected to the plurality of data lines D is turned on and a firstsignal V1 applied to a first test signal line TEST_DATA1 is applied tothe plurality of data lines D. The first signal V1 may be a signal, bywhich the plurality of pixels R, G, and B displays white, and theplurality of pixels R, G, and B may display white if the first signal V1is applied to the plurality of data lines D.

If a gate off signal is applied to the first test gate line TEST_GATE,when the gate on signal is applied to the second test gate line DC_GATEfor a second time H2, the second switching element Q2 connected to theplurality of data lines D is turned on, so that a second signal V2applied to the plurality of second test signal lines CLA, CLB, and CLCis applied to the plurality of data lines D. The second signal V2 may bea signal, by which the plurality of pixels R, G, and B displays black,and the plurality of pixels R, G, and B may display black if the secondsignal V2 is applied to the plurality of data lines D.

For example, when a crack is generated in the non-display area NDA byapplying an external impact or force to the display device, the firstcrack detection line CD1 and the second crack detection line CD2 may bedamaged.

Accordingly, resistance of the data line D connected to the first crackdetection line CD1 and resistance of the data line D connected thesecond crack detection line CD2 may increase, and thus, a voltage V_Tapplied to the pixel connected to the first crack detection line CD1 andthe pixel connected the second crack detection line CD2 may both fail tobe charged up to the second signal V2 and may have a voltage differenceΔV with the second signal V2.

The voltage difference ΔV may be generated, so that the pixel connectedto the first crack detection line CD1 and the second crack detectionline CD2 may fail to display the color black and may illuminate at arelatively high intensity. Based on this voltage difference ΔV, it maybe possible to detect a crack generated in the non-display area NDAadjacent to the border of the display area DA.

The step wiring portions CDp included in the first crack detection lineCD1 and the second crack detection line CD2 may enable the first crackdetection line CD1 and the second crack detection line CD2 to be moresusceptible to being damaged by a crack generated in the non-displayarea NDA, thereby more effectively detecting a crack generated in thenon-display area NDA.

In addition, the stepped wiring unit CDp may include the first portionCDpa and the second portion CDpb having the height difference to allowthe first crack detection line CD1 and the second crack detection lineCD2 to be positioned in a wider area. Compared to the case where thecrack detection line has a plane form positioned on substantially thesame layer and having substantially the same surface height (e.g.,without a step in the crack detection line), the case where the crackdetection line has a form having a repeated height difference and thecrack detection line is also positioned on the surface and the lateralsurface of the insulating layer has an increased probability ofdetecting a crack generated in the insulating layer.

Further, when a crack is generated in the insulating layer, stress isconcentrated to a corner portion of the lateral wall of the insulativestep portion ILp, so that a crack and the like may be generated in thefirst crack detection line CD1 and the second crack detection line CD2positioned on the corner of the lateral wall of the insulative stepportion ILp. Accordingly, when a crack is not directly generated in thefirst crack detection line CD1 and the second crack detection line CD2,but is generated only in the insulating layer, it is possible to detectthe crack.

Hereinafter, a display device according to an exemplary embodiment ofthe present invention will be described with reference to FIGS. 6 to 8.The display device of an exemplary embodiment of the present inventionwill be described based on a difference from the display device of anaforementioned exemplary embodiment of the present invention, anddescriptions of elements that may be assumed to be similar to those ofan aforementioned exemplary embodiment of the present invention may beomitted.

FIG. 6 is a top plan view schematically illustrating a disposition of acrack detection line in a display device according to an exemplaryembodiment. FIG. 7 is a layout view of the display device according toan exemplary embodiment, and FIG. 8 is a cross-sectional view takenalong line VIII-VIII of FIG. 6.

A first crack detection line CD1 and a second crack detection line CD2are disposed at both sides of a display area DA, respectively, so as toat least partially surround the display area DA, in which the pluralityof pixels R, G, and B is positioned.

The first crack detection line CD1 extends in a first direction R1 froma first connection portion CP1 a along a non-display area NDA adjacentto a border of the display area DA, in which the plurality of pixels R,G, and B is formed

The first crack detection line CD1 may be divided into a first line CDlaand a second line CDlb while extending in the first direction R1. Athickness of each of the first line CDla and the second line CDlb may besmaller than that of the first crack detection line CD1, and a sum ofthe thicknesses of the first line CDla and the second line CDlb may besubstantially the same as a thickness of the first crack detection lineCD1. The first line CDla and the second line CDlb are joined again forthe first crack detection line CD1 to change direction and return in asecond direction R2 that is an opposite direction to the first directionR1. The first crack detection line CD1 is divided into the first lineCDla and the second line CDlb again while extending in the seconddirection R2. The first line CDla and the second line CDlb of the firstcrack detection line CD1 are joined again near a second connectionportion CP1 b. However, exemplary embodiments of the present are notlimited thereto. For example, the first crack detection line CD1 mayinclude more lines than just a first line CDla and a second line CDlb.

Similarly, the second crack detection line CD2 extends in the firstdirection R1 from a third connection portion CP2 a along the non-displayarea NDA adjacent to the border of the display area DA, in which theplurality of pixels R, G, and B is formed

The second crack detection line CD2 is divided into a first line CDlaand a second line CDlb again while extending in the first direction R1.A thickness of each of the first line CDla and the second line CDlb maybe smaller than that of the second crack detection line CD2, and a sumof the thicknesses of the first line CDla and the second line CDlb maybe substantially the same as a thickness of the second crack detectionline CD2. The first line CDla and the second line CDlb are joined againfor the second crack detection line CD1 to change direction and returnin the second direction R2 that is an opposite direction to the firstdirection R1. The second crack detection line CD2 is divided into thefirst line CDla and the second line CDlb again while extending in thesecond direction R2. The first line CDla and the second line CDlb of thesecond crack detection line CD2 are joined again near a fourthconnection portion CP2 b.

The first crack detection line CD1 includes a plurality of repeatedlypositioned stepped wiring units CDp. The stepped wiring unit CDpincludes a first portion CDpa and a second portion CDpb having a heightdifference. The stepped wiring unit CDp of the first crack detectionline CD1 includes a second portion CDpb overlapping an insulative stepportion ILp, and the first portion CDpa does not overlap an insulativestep portion ILp. The insulative step portion ILp provides a step to thefirst crack detection line CD1, and a height of a surface of the firstcrack detection line CD1 is changed according to whether the first crackdetection line CD1 overlaps the insulative step portion ILp. Forexample, the stepped wiring unit CDp has a step along a surface of theinsulative step portion ILp. The second portion CDpb of the steppedwiring unit CDp is positioned on a surface of an upper portion of theinsulative step portion ILp, and the first portion CDpa is positioned atsubstantially the same height as that of the lower portion of theinsulative step portion ILp. The first portion CDpa and the secondportion CDpb are connected along a lateral wall of the insulative stepportion ILp. The first portion CDpa and the second portion CDpb have aheight difference corresponding to a height of the insulative stepportion ILp. For example, the second portion CDpb overlaps theinsulative step portion ILp, and the first portion CDpa does not overlapthe insulative step portion ILp. Accordingly, the first crack detectionline CD1 has a form, in which the high second portion CDpb and the lowfirst portion CDpa, which both form the height difference correspondingto the height of the insulative step portion ILp, are repeated in theextension direction of the first crack detection line CD1.

In addition, the second crack detection line CD2 may include a steppedwiring unit CDp including the first portion CDpa and the second portionCDpb having a height difference. Further, the forms of the first crackdetection line CD1 and the second crack detection line CD2 may besubstantially the same as each other.

As described above, when the first crack detection line CD1 and thesecond crack detection line CD2 are divided into the first line CDla andthe second line CDlb, each of which has a smaller thickness than that ofthe first crack detection line CD1, it is possible to detect a crackmore effectively compared to a case where the crack detection line isformed of one non-divided wire. In the case where the crack detectionline is formed of one non-divided wire, when a crack is generated at apart of the crack detection line and a current flows through a portionof the crack detection line, which is not damaged, it may be difficultto detect a damage of the crack detection line. However, in the casewhere the first crack detection line CD1 and the second crack detectionline CD2 are divided into the first line CDla and the second line CDlb,each of which has a smaller thickness than that of the first crackdetection line CD1, even though a crack is generated only at a part ofthe crack detection line, it may be difficult for a current to flowthrough a portion that is not damaged. Accordingly, it may be possibleto detect damage to a part of the crack detection line.

Many of the characteristics of the display devices according to anexemplary embodiment of the present invention described with referenceto FIGS. 1 to 5 may be applied to an exemplary embodiment of the presentinvention described hereinafter.

Hereinafter, a display device according to an exemplary embodiment ofthe present invention will be described with reference to FIG. 9. Thedisplay device of an exemplary embodiment of the present invention willbe described based on a difference from the display device of anaforementioned exemplary embodiment of the present invention, anddescriptions of elements that may be assumed to be similar to those ofan aforementioned exemplary embodiment of the present invention may beomitted.

FIG. 9 is a schematic cross-sectional view of a display device accordingto an exemplary embodiment. A first area A of FIG. 9 represents across-section of a part of one pixel in the display area of the displaydevice. A second region B of FIG. 9 represents a cross-section of aportion of the non-display area of the display device, through which acrack detection line CD passes, taken along in a direction extendingalong an extension direction of the crack detection line CD.

The crack detection line CD includes a plurality of repeatedlypositioned stepped wiring units CDp. The stepped wiring unit CDpincludes a first portion CDpa and a second portion CDpb having a heightdifference, and the first portion CDpa and the second portion CDpb maybe connected in a form of a curve which is not angulated. The crackdetection line CD has a form, in which the first portion CDpa and thesecond portion CDpb are repeatedly present in an extension direction ofthe crack detection line CD, so that a predetermined height differenceis repeated.

The stepped wiring unit CDp of the crack detection line CD includes thesecond portion CDpb overlapping an insulative step portion ILp and thefirst portion CDpa, which does not overlap the insulative step portionILp. For example, the insulative step portion ILp may be positionedunder a part of the stepped wiring unit CDp, and a surface of theinsulative step portion ILP may be curved. The insulative step portionILp provides a step to a first crack detection line CD1, and a height ofa surface of the first crack detection line CD1 is changed according towhether the first crack detection line CD1 overlaps the insulative stepportion ILp. For example, the stepped wiring unit CDp has a step along asurface of the insulative step portion ILp. The plurality of insulativestep portions ILp is repeatedly disposed in the extension direction ofthe first crack detection line CL1 with a predetermined interval. Theplurality of insulative step portions ILp may include at least a part ofsequentially disposed second to fourth insulating layers IL2, IL3, andIL4.

The second portion CDpb of the crack detection line CD may be positionedon substantially the same layer as that of a source electrode SE, andthe first portion CDpa of the crack detection line CD may be positionedon substantially the same layer as an active layer AL.

A lot of characteristics of the display devices according to exemplaryembodiments of the present invention described with reference to FIGS. 1to 5, and FIGS. 6 to 8 may be applied to other exemplary embodiments ofthe present invention.

According to the display device according to aforementioned exemplaryembodiments of the present invention, it may be described that thedisplay device includes the encapsulating unit, but the display deviceaccording to an exemplary embodiment of the present invention is notlimited thereto. Further, the form and the height of the insulative stepportion ILp may be various, and correspondingly, the form of the crackdetection line CD and a height difference between the first portion CDpaand the second portion CDpb may also be various. For example, the secondportion CDpb may be positioned on the same layer as that of the sourceelectrode SE and the first portion CDpa may be positioned on the samelayer as that of the gate electrode GE. In addition, the second portionCDpb may be positioned on the same layer as that of the gate electrodeGE and the first portion CDpa may be positioned on the same layer as theactive layer AL. Further, the forms (e.g., shape) and the heights of theplurality of insulative step portion ILps may be different from oneanother.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be apparent tothose of ordinary skill in the art that various changes in form anddetail may be made thereto without departing from the spirit and scopeof the present invention.

What is claimed is:
 1. A display device, comprising: a substrateincluding a display area and a non-display area; a plurality of pixelsin the display area of the substrate; a plurality of gate lines and aplurality of data lines respectively connected to the plurality ofpixels; a plurality of first regions disposed in the non-display area ofthe substrate and arranged in a first direction repeatedly to sides ofthe display area; and a crack detection line in the non-display area andextending primarily in the first direction, wherein the crack detectionline includes a first portion which does not overlap the plurality offirst regions, and a second portion overlapping each of the firstregions, each of the plurality of first regions comprises at least oneinsulating layer, and the first portion of the crack detection line isnot electrically connected to any elements.
 2. The display device ofclaim 1, wherein the crack detection line is not in the display area. 3.A display device, comprising: a substrate including a display area and anon-display area; a plurality of pixels in the display area of thesubstrate; a plurality of gate lines and a plurality of data linesrespectively connected to the plurality of pixels; a plurality of firstregions disposed in the non-display area of the substrate and arrangedin a first direction repeatedly to sides of the display area; and acrack detection line in the non-display area and extending primarily inthe first direction, wherein the crack detection line includes a firstportion which does not overlap the plurality of first regions, and asecond portion overlapping each of the first regions, wherein the firstportion and the second portion of the crack detection line are atdifferent heights from each other, wherein the second portion of thecrack detection line is on a surface of an upper portion of a firstregion of the plurality of first regions, wherein the first portion ofthe crack detection line is at substantially the same height as that ofa lower portion of the first region of the plurality of first regions,and wherein the first portion of the crack detection line is notelectrically connected to any elements.
 4. The display device of claim3, wherein the crack detection line is connected to at least one dataline of the plurality of data lines.
 5. The display device of claim 4,wherein the crack detection line at least partially surrounds thedisplay area of the substrate.
 6. The display device of claim 5, whereinthe plurality of first regions includes an organic material or aninorganic material, and at least partially surrounds the display area ofthe substrate.
 7. The display device of claim 4, wherein the secondportion is on substantially the same layer as that of the data line, andthe crack detection line includes substantially the same material asthat of the data line.
 8. The display device of claim 7; wherein thefirst portion is directly on the substrate.
 9. The display device ofclaim 7, further comprising an insulating layer on the substrate,wherein the first portion is on the insulating layer.
 10. The displaydevice of claim 7, further comprising: an active layer connected withthe data line, wherein the first portion is at substantially the sameheight as that of the active layer.
 11. The display device of claim 4,wherein the plurality of first regions have substantially the same form.12. The display device of claim 4, wherein a part of the crack detectionline is divided into a first line and a second line.
 13. A displaydevice, comprising: a substrate including a display area and anon-display area; a plurality of pixels in the display area of thesubstrate; a plurality of gate lines and a plurality of data linesrespectively connected to the plurality of pixels; a plurality of firstregions disposed in the non-display area of the substrate and arrangedin a first direction repeatedly to sides of the display area; and acrack detection line in the non-display area and extending primarily inthe first direction, wherein the crack detection line includes a firstportion which does not overlap the plurality of first regions, and asecond portion overlapping each of the first regions wherein the firstportion and the second portion of the crack detection line are atdifferent heights from each other, and wherein the second portion of thecrack detection line is on a surface of an upper portion of a firstregion of the plurality of first regions, and the first portion of thecrack detection line is at substantially the same height as that of alower portion of the first region of the plurality of first regions,wherein the crack detection line is connected to at least one data lineof the plurality of data lines, a part of the crack detection line isdivided into a first line and a second line, and a sum of thicknesses ofthe first line and the second line is equal to or smaller than athickness of the crack detection line.
 14. A display device, comprising:a substrate including a first area and a second area surrounding thefirst area; a plurality of first regions disposed in the second area ofthe substrate and arranged in a first direction repeatedly to a side ofthe first area; a crack detection line in the second area and extendingprimarily in the first direction, wherein the crack detection lineincludes a first portion and a second portion, wherein the first portionis between each first region of the plurality of first regions, and thesecond portion overlaps each of the first regions, and wherein the crackdetection line is divided into a plurality of lines.
 15. The displaydevice of claim 14, wherein the plurality of lines recombines near afirst end and a second end of the crack detection line.
 16. The displaydevice of claim 14, wherein the first portion is on the substrate, andthe first portion and the second portion are at different heights fromeach other.
 17. The display device of claim 16, wherein the firstportion and the second portion are connected to each other along alateral wall of each first region of the plurality of first regions. 18.A display device, comprising: a substrate including a display area and anon-display area surrounding the display area; a plurality of firstregions disposed in the non-display area and arranged in a firstdirection repeatedly to a side of the display area with a predeterminedinterval; a first insulating layer disposed on the substrate; and acrack detection line on the plurality of first regions; wherein thecrack detection line includes a first portion and a second portion,wherein the second portion overlaps an upper portion of a first regionof the plurality of first regions and the first portion is adjacent toat least one first region of the plurality of first regions, and whereina bottom surface of the first portion of the crack detection linedirectly contacts only the first insulating layer without electricallyconnecting to any elements.
 19. The display device of claim 18, whereinthe first portion and second portion have a curvature.
 20. The displaydevice of claim 18, wherein the first portion is on the substrate.
 21. Adisplay device, comprising: a substrate including a display area and anon-display area surrounding the display area; a plurality of firstregions disposed in the non-display area and arranged in a firstdirection repeatedly to a side of the display area with a predeterminedinterval; a first insulating layer disposed on the substrate; and acrack detection line on the plurality of first regions; wherein thecrack detection line includes a first portion and a second portion,wherein the second portion overlaps an upper portion of a first regionof the plurality of first regions and the first portion is adjacent toat least one first region of the plurality of first regions, wherein abottom surface of the first portion of the crack detection line directlycontacts the first insulating layer, and wherein the crack detectionline has a serpentine pattern winding up and down in a directionperpendicular to a plane of the substrate.
 22. The display device ofclaim 1, wherein the each of the plurality of first regions comprises atleast two or more insulating layers.